Remember the Astrodome!

Less than 100 feet away from the site of this year's Super Bowl—Houston's modern, retractable-roof NRG Stadium—sits the father of all indoor stadiums, ugly and modern. As thousands of screaming football fans stroll right past the aging Astrodome to see the Patriots take on the Falcons on Feb. 5, the venue's storied history will be the only thing protecting its future.

David Bush, executive director of Preservation Houston, says the big building has defined a city for more than 50 years. "It put Houston on the map," Bush says. "People still identify Houston with the Astrodome." More than that, the dome was the model for all stadiums that came after it, changing the game for how sports stadiums and other huge structures would be built.

If You Build It

Construction started in 1962, when the Houston Colt .45s joined Major League Baseball (they'd be renamed the Astros in '65 when they moved into the new dome). The city promised to give its fans the world's first domed sports stadium, one that would be twice as large as any single enclosed structure ever built. The stadium would be half a mile around if you walked the entire concourse.

Building a roof over such a monstrosity required lots of modeling and wind-tunnel testing, including at McDonnell Aircraft Corporation labs, before architects and engineers finally settled on a steel lamella-type trussed roof structure. This design uses arched ribbing five to six feet deep across the entire roof. With the help of a 376-ton tension ring, the dome could handle the pressures of wind loading. In sum, it took 2,150 tons of steel to create the 350,000 square feet of roof frame that rises 202 feet above the playing field.

Astrodome, 1965.

Then they had to figure out how to build it. Engineers developed a construction method, which included 37 steel towers to erect the dome framing in pie sections. Jacks at the top of the towers kept the tension ring vertical and allowed crews to slowly offload pressure from the towers to the steel column supports.

Trendsetter

When it opened in 1965, the Astrodome not only set new standards in engineering and roof construction, but also in the way sports stadiums were built—for better or worse. The first animated videoboard seen was installed in Houston, and so was luxury box seating behind glass.

View of Lamella roof truss.

When the park opened, the translucent roof washed sunlight over the indoor natural grass, but the glare was so bad workers painted the roof to block the sun. Because the stadium was now completely cut off from sunlight, the Astrodome was first to use the synthetic grass. Thus, the name AstroTurf was born.

The artificial surface wasn't the only trend born in the Astrodome. Soon the stadium's oversized roundness sparked a revolution in cookie-cutter stadium design that lasted decades, seen most clearly in Minneapolis' Metrodome, Indianapolis' RCA Dome, Seattle's Kingdome, and many more.

Sticking It Out

Houston Astros game in the Astrodome, 1968 MLB All Star Game.

Focus on SportGetty Images

Most of the cookie-cutter stadiums are gone now, replaced by glitzy new structures with angular designs that better reflect 21st century style. Because of its historical significance, though, the Astrodome hasn't met the same fate as the very stadiums it's inspired. Bush says the local county government led the push to retain the building, even though it was losing money every year since officially closing in 2006, two years after providing vital aid during Hurricane Katrina.

Voters approved in 2016 to save the Astrodome, agreeing to a $105 million retrofit that will raise the floor level roughly 20 feet to install 1,400 parking spaces. The hope is that these renovations will make the Astrodome an attractive venue to rent, rather than being just a glorified parking lot.

Now that the Astrodome is under consideration as a Texas State Antiquities Landmark, the only thing that must remain untouched is the stadium's volume. "That is what made the dome the dome," Bush says. "The underground portion and the majority of the space inside the dome [would be] preserved."

Bush says adding parking and making the site more attractive for trade shows—like rodeos, a a huge money-maker in Houston—is the best chance at saving the building. "[This plan] preserves the dome," Bush says, "so if in 10, 20 or 50 years from now somebody comes up with a really good idea...it will still be there."

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